Friction, Lubrication and the Lubricants in Horology

Chapter V

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THE PROPERTIES AND RELATIVE VALUES OF LUBRICANTS IN HOROLOGY.

~62. Lubrication~ has for its objects, both the reduction of friction and the prevention of excessive injury from wear; and the mechanician resorts to the expedient of interposing between the rubbing surfaces a substance having the lowest possible coefficient of friction with the greatest possible capacity for preventing wear.

The valuable qualities of lubricants are determined by their power of reducing friction, and by their endurance as well as that of the surfaces on which they are used. The amount of frictional resistance to the motion of machinery is obviously determined by the character of the lubricating material.[12]

~63. The Animal Oils~ have had a wide and varied application in general machinery, and much testimony might be produced to show the superiority of any one kind over all the other kinds. Each variety has some particular property which some of the others may not have to such a degree.

~64. Porpoise Jaw Oil[13] and Blackfish Melon Oil~ have certain good qualities which have made them very popular, particularly on this side of the Atlantic. When properly refined (4-6) they are no doubt very suitable for the work of reducing friction in small and delicate mechanism.

~65. Sperm Oil~ (7) had been used to some extent as a lubricant for time-keeping contrivances; in fact, many tower clock experts still employ it on the heavier bearings. A. Long, writing to the British Horological Journal, describes a trip to the Arctic regions in 1814 and 1815, in which he states that a certain portion of the sperm oil they obtained never congealed, which they preserved and applied to their chronometers, and thus kept them going through the winter.

Others have experimented with it, and it was at one time largely used; while some tower clock makers claim that they find it satisfactory. It is, however, open to the objection that it would produce serious variation when used in time-keeping mechanisms, as its _viscosity varies greatly with varying temperatures_ caused by the alteration of the spermaceti it contains, thus causing sudden fluctuations of its coefficient of friction (81). It also absorbs oxygen rapidly when it is exposed to the air and loses quality seriously, gradually becoming "gummed" or resinous. A gain of two to three per cent in weight in twelve hours when exposed to the air at 140 deg. F. (60 C), is caused by this absorption of oxygen (10).

~66. Bone Oil~ (8) has been widely used both in this country and in Europe, and possesses some good qualities, not the least of which is the property of resisting evaporation and oxidation.

~67. Neatsfoot Oil~ (9) has been largely used, especially in Europe. The writer regrets that he has not procured samples in order to ascertain its relative value.

~68. Olive Oil~ (10) has at least one good quality. It is one of the most perfectly non-drying of all the oils, resisting both oxidation and evaporation (24). But it is next to impossible to entirely remove its acid qualities, small traces of which remain after the most thorough treatment. It is also liable to decomposition, generating acids even after refinement.

~69. Mineral Oil~ (11) has been used as a lubricant for time keeping mechanism; but as there are so many varieties on the market, each differing from the others and possessing properties peculiar to itself, and as many have made experiments which have not demonstrated that such oils possess all the essential qualities of a perfect lubricant in horology, the author believes that the abundance of kinds and qualities of mineral oils has in the past been more or less confusing to the majority of those who have experimented; and believes further, that if the proper kind and quality of such oils had been used, all that could be desired in a lubricant would have been shown to have been contained therein.

Past experience has shown that many lubricants remained for years unused for special purposes to which, when tried, they were found specially adapted.

Though E. Rigg was probably in error in the matter previously discussed (44) his otherwise excellent lecture contains the following:--[14]

"But there is another subject that has a still closer bearing on friction as met with in time keeping instruments, and I cannot bring my lecture to a close without reference to that most fruitful source of trouble to the watchmaker--oil. Breguet, a very famous horologist, and D'Arcet, an equally celebrated chemist, worked together at this problem and what was the result? They produced an oil that was, according to their theory, perfect; but when applied to watches it proved to be worse than the ordinary oils of commerce. Since their day the chemistry of oil has not made much progress, and the methods recommended for testing oil are still very ineffectual. The only test of any use is actual trial for a long period, and under varying conditions as to temperature, nature of atmosphere, etc.; and there are several oils on the market more or less satisfying the required conditions. So far as my knowledge goes, however, all are liable to dry; and this prompts me to draw your attention to a lubricator that has come into use for heavy machinery in recent years, in the hope that it may afford a suggestion for the improvement of watch oils. I allude to the mixture of certain kinds of mineral oil with an oil that has a tendency to dry. Even a small percentage is asserted to entirely check this tendency and the resulting mixture is said to have the property of not in any way acting on or damaging the metal to which it is applied. The thickness, or 'body,' is made to vary according to the pressure to which the oil is subjected. * * * * Would it be oversanguine to hope that some such mixture, prepared from perfectly pure materials, might help even the chronometer maker to secure more uniform rates? Absolute freedom from acidity means a reduction of such electrical action as may occur at the pivots, and, therefore, a greater permanency of the oil from this point of view."

~70. Neutral Oil~ (14) seems to be especially adapted for use in horology. Used in a pure state, or mixed in variable quantities with a good animal oil, it can readily be made to fulfill the various conditions required in all parts of watches, chronometers, mantel and tower clocks.

It is usually sold as such, but sometimes under the names "liquid paraffine," "glycoline," "albolene," etc., while "solid paraffine," "white cosmoline," "solid alboline," are the names given to the thick butyraceous mass from which neutral oils are made. Sometimes this substance, as well as the liquid paraffine, is medicated or perfumed; but it is hardly necessary to state that when thus treated it is unfit for use in horology.

~71. The Properties of Neutral Oil~ are stated to be:[15]

"It is a clear oily liquid, having a specific gravity of not less than 0.840 and boiling not below 360 deg. C. (680 deg. F.). It should be free from colored, fluorescing, and odorous compounds.

"When heated for a day by means of a water bath, the paraffine should not become dark colored, and the sulphuric acid should become only slightly brownish. Metallic sodium treated in a similar manner should retain its metallic lustre. Alcohol boiled with paraffine should not have an acid reaction."

~72. The Properties of Solid Paraffine~ (13) are given as follows:[16]

"The melting point of commercial paraffine varies much. Obtained from the residuum of petroleum distillation it is usually 43 deg. C. (109.4 F.), or somewhat higher."

The acid and metallic sodium tests given for liquid paraffine will apply to the solid paraffine.

~73. The Value of a Lubricant~ _as_ a lubricant is independent of the market price; and it is at a maximum, according to Thurston, when it possesses the following characteristics:

1. Enough "body," or combined capillarity and viscosity (82), to keep the surfaces between which it is interposed from coming in contact at maximum pressures.

2. The greatest fluidity consistent with the preceding requirements, i. e., the least fluid friction allowable.

3. The lowest possible coefficient of friction under the conditions in actual use, i. e., the sum of the two components, solid and fluid friction, should be a minimum.

4. A maximum capacity for receiving, transmitting, storing and carrying away heat.

5. Freedom from tendency to decompose or to change in composition by gumming or otherwise, on exposure to the air (79) while in use.

6. Entire absence of acid or other properties liable to produce injury of materials or metals (77) with which they may be brought in contact.

7. A high temperature of vaporization and a low temperature (83) of solidification.

8. Special adaptation as to speed and pressure of rubbing surfaces under which the unguent is to be used.

9. It must be free from grit and from all foreign matter.

The author will add that for use in horology:

10. It must possess a minimum variation of viscosity (84) in varying temperatures.

The writer can see no reason why a mineral oil which has been properly refined _and of the proper consistency_, either alone or mixed with animal oil, could not be used to great advantage in horology. Indeed, the possibilities in this direction seem to be so pregnant with promises of good results that some space will be devoted to the matter.

~74. The Special Advantages of Mineral Oils~ as lubricants in horology are:

1. Mineral oils can be made entirely pure, and possess uniform and known properties when derived from the same or a similar source; while the quality of animal and vegetable oils varies from year to year, depending, in animal oils, on the season of the year when the crude oil is obtained, on the age and condition of the animal, and on the kind, quality and quantity of food which it had (5) recently consumed; and in vegetable oils on the season, soil, climate and method of treatment.

2. According to Thurston "All vegetable and animal oils are compounds of glycerine with fatty acids. When they become old, decomposition takes place and the acid is set free, by which action the oils become rancid. This rancid oil or acid will attack and injure machinery. Again, all animal oils contain more or less gummy matter, which accumulates when exposed to the action of the atmosphere, and will, consequently, retard the motion of the machinery."

3. Spon, in his Encyclopedia of the Arts, gives his views to the effect that "The best oil is that which has the greatest adhesion to metallic surfaces and the least cohesion in its own particles. In this respect fine mineral oils stand first, sperm oil second, neatsfoot oil third. Consequently the best mineral oils are the best for light bearings. The best oil to give body to fine mineral oils is sperm oil."

4. "Mineral oils do not absorb oxygen," and consequently do not "gum" or become viscous.--Thurston.

5. Mineral oils never become rancid in any climate, as they possess no fatty acids.

6. Mineral oils produce very little fluid friction.

7. Mineral oils withstand a high temperature without decomposition or vaporization, and a low temperature without solidification.

8. Properly prepared mineral oils are free from grit and all foreign substances.

9. In addition to the above, a minor property of mineral oil is that they are very cheap comparatively, while they do not possess any odor if properly refined.

10. The variation of viscosity in varying temperatures is less in mineral oils than in animal or vegetable oils.

~75. Methods of Testing Oils~ are necessary in order to determine which may be adapted to a specific purpose. Their peculiar characteristics must be studied in order to know which will best fulfill the conditions arising in actual practice. Experiments are necessary in which the oil is subjected to conditions approximating, as nearly as possible, to the conditions proposed in its actual use.

Saunier states[17] that "success depends largely on the skill of the manipulator; and if he is not endowed with the power of judging, _mainly by the taste_, whether oil satisfies certain prescribed conditions, he can never be certain of the result." As the author's abilities in this regard are not up to the required standard, and as some oils are sometimes in such a state of decomposition that even the odor is unpleasant, he has used other, and perhaps more satisfactory, methods of determining the relative values of the various oils.

The following experiments show the relative values of oils that have been, or may be, used in horology:

J. J. Redwood has made experiments on the action of oils upon metals, especially for the purpose of determining which oils were best adapted for use on the various metals and for ascertaining which oils were most suitable for mixing as lubricants. He has tabulated the results of his researches in two tables, which show that:[18]

_Mineral oil_ has no effect upon copper and zinc, and attacks lead most.

_Olive oil_ attacks copper most, tin least.

_Sperm oil_ attacks zinc most, copper least.

The experiments show, on the other hand, that:

_Brass_ is attacked most by olive oil.

_Copper_ is not attacked by mineral lubricating oil, least by sperm oil.[19] Dr. Watson states in regard to this action:

1. That of the oils used, viz., olive sperm, neat's-foot, and paraffine, the samples of paraffine oil on copper was least affected, and that sperm was next in order of inaction.

2. That the appearances of the paraffine oil and the copper were not changed after an exposure of 77 days.

He later[20] experimented further with the following results noted, after one day's exposure, with iron:--

1. _Neat's-foot._--Considerable brown irregular deposit on metal. The oil slightly more brown than when first applied.

2. _Sperm._--Slight brown deposit with irregular markings on the metal. Oil of dark brown color.

3. _Olive._--Clear and bleached by exposure to light and air. The appearance of metal the same as when first immersed.

4. _Paraffine._--Oil bright yellow and contains a little brown deposit.

The action of oils on iron exposed to their action for twenty-four hours and on copper after ten day's exposure was found to have been:--

TABLE II.

ACTION OF OILS ON METALS.

~76. Various Experiments~ have been made by the writer with a number of oils that may be, or have been, used in horology, as well as with the principal watch oils on the market. At first he did not intend to mention the names of the manufacturers; but, after seeking advice of several eminent watchmakers, and on mature consideration, he decided to do so for the following reasons:--

1. The object of the Society before which these lectures were delivered[21] is "to promote and to secure concerted action for the purpose of _mutual_ improvement in the practice of our profession as horologists, by a study of both the practical and theoretical divisions of the science and art of horology; _to publish the results of such study for the benefit of all in the profession_; _to preserve the same for the use of our successors_; to elevate the standard of workmanship; and to encourage in the members a higher conception of what our art really is."

As this object cannot be attained without the names of manufacturers being mentioned in connection with their oils, the author considers that this is sufficient justification.

2. No injustice can have been done the manufacturers when the author states that the results obtained by him are not to be considered as conclusive evidence regarding the properties of the oils tested, as the samples he used may have been better than, or not so good as, the usual output of the manufacturers whose names were on the labels.

3. Some of the manufacturers of oils sent samples subject to the condition of the publication of the results, with the request that the oils should be submitted to test, and if found wanting, they (the manufacturers) certainly wished to know it.

TABLE III.

FOR REFERENCE.

[Transcriber's note: Table Split for Text file]

----------------------+----------------------------------------+
| MANUFACTURER. |
+----------------------------------------+
SYMBOLS | | |
EMPLOYED. | NAME. | LOCATION. |
| | |
----------------------+--------------------+-------------------+
[B]E. K. w | Ezra Kelley | New Bedford, Mass.|
| | |
| | |
[B]W. F. N. w | W. F. Nye | New Bedford, Mass.|
| | |
| | |
[A]D. C. S. w | D. C. Stull |Provincetown, Mass.|
| | |
| | |
[A]D. C. S. ch | D. C. Stull |Provincetown, Mass.|
| | |
| | |
[A]D. C. S. cl | D. C. Stull |Provincetown, Mass.|
| | |
| | |
[B]W. C. w | W. Cuypers | Dresden, Germany |
| | |
[A]B. & K. w | Breitinger & Kunz | Philadelphia, Pa. |
| | |
[A]S. B. & Co. wc |Stevenson Bro. & Co.| Philadelphia, Pa. |
| | |
[A]C. L. Co. w | Chem. Lub'g Co. | Brooklyn, N. Y. |
| | |
[A][C]C. L. Co. No . 1| Chem. Lub'g Co. | Brooklyn, N. Y. |
| | |
[A][C]Glyc | Bullock & Crenshaw | Philadelphia, Pa. |
| | |
[B][C]Alb. f | McKesson & Robbins | Philadelphia, Pa. |
| | |
[B][C]Alb. s | McKesson & Robbins | Philadelphia, Pa. |
| | |
[B][C]Sp | ----? | ----? |
| | |
[B][C]Ol | ----? | ----? |
----------------------+--------------------+-------------------+

---------------------+-------------------------------------------------------
| OIL.
|-----------------------------+--------------------------
SYMBOLS | | | SOURCE.
EMPLOYED. | KIND. | NAME. |--------------------------
| | | GENERIC.| SPECIFIC.
---------------------+-------------+---------------+---------+----------------
[B]E. K. w | Watch | Superfine | Animal | Porpoise jaw or
| | | |blackfish--melon
| | | |
[B]W. F. N. w | Watch | Superior | Animal | Porpoise jaw or
| | | |blackfish--melon
| | | |
[A]D. C. S. w | Watch | Superfine | Animal | Porpoise jaw or
| | | |blackfish--melon
| | | |
[A]D. C. S. ch | Chronometer | Superfine | Animal | Porpoise jaw or
| | | |blackfish--melon
| | | |
[A]D. C. S. cl | Clock | Superfine | Animal | Porpoise jaw or
| | | |blackfish--melon
| | | |
[B]W. C. w | Watch | Superfine | Animal | Bone
| | | |
[A]B. & K. w | Watch | Superfine | Animal | Bone
| | | |
[A]S. B. & Co. wc |Watch & clock| Album | Mineral | Neutral
| | | |
[A]C. L. Co. w | Watch | Perfect | Mixed |Neutral & ---- ?
| | | |
[A][C]C. L. Co. No. 1| Lubricating | No. 1 Synolene| Mineral | Neutral
| | | |
[A][C]Glyc | Lubricating | Glycolene | Mineral | Neutral
| | | |
[B][C]Alb. f | Lubricating |Fluid alboline | Mineral | Neutral
| | | |
[B][C]Alb. s | Lubricating |Solid alboline | Mineral | Paraffine
| | | |
[B][C]Sp | Lubricating | ----? | Animal | Sperm, whale
| | | |
[B][C]Ol | Lubricating | ----? |Vegetable| Olive
---------------------+-------------+---------------+---------+----------------

[Note A: Obtained as sample from manufacturer.]

[Note B: Purchased in open market.]

[Note C: Not sold as watch oil.]

4. On hearing of these experiments, others in the profession may be tempted to make similar or other investigations and publish them.

5. In that case, if the results of many experiments demonstrate the superiority of one particular kind of oil, the whole profession will be profited thereby.

6. The manufacturers of oils may be caused to exert their utmost to keep abreast of the times, and will see for themselves in what way their oils may not fulfill the required conditions, thereby being the better prepared to overcome the difficulties with which they meet.

For the sake of convenience the author has tabulated a list of the oils which he has subjected to various tests, showing the name, kind and source of each oil tested; also those which were obtained as samples, and those which were purchased in open market, as well as those which were not sold as watch oils, but which may be tried.

This is shown in table III.

~77. The Action Of Oils On Brass~ has been determined by the author by using a piece of good sheet brass into which suitable recesses were made for the retention of the various oils. This plate was submitted to the action of the air at temperatures varying from 24 deg. to 37.5 deg. C. (about 76 deg. to 100 deg. F.), for 100 days.

The results of this test are shown in Table IV. A further test, under different conditions, gave results as shown in Table V.

TABLE IV.

ACTION OF OILS ON BRASS.

Temp. 21 deg. to 37.5 deg. C. = 70 deg. to 100 deg. F. Time 100 days.

TABLE V.

ACTION OF OILS ON BRASS.

Temp. 5.5 deg. to 21 deg. C. = 40 deg. to 70 deg. F. Time 25 days.

---------------------+--------------------------------------- SYMBOLS | CONDITION. ACCORDING TO +-------------------+------------------- TABLE III. | OF OIL. | OF BRASS. ---------------------+-------------------+------------------- E. K. w. | Very Light Brown. | No change. W. F. N. w. | " " " | " " D. C. S. w. | " " " | " " D. C. S. ch. | " " " | " " D. C. S. cl. | " " " | " " W. C. w. | No change. | " " B. & K. w. | " " | " " S. B. & Co. w. & cl. | " " | " " C. L. Co. w. | " " | " " C. L. Co. No. 1 | " " | " " Glyc. | " " | " " Alb. f. | " " | Very light brown. Alb. s. | " " | Unaltered. ---------------------+-------------------+-------------------

~78. The Effect of Oils on Steel~, with a view of ascertaining their rust preventing properties, especially to see if the treatment of hairsprings with a _very_ slight film of oil (56), would prevent rust in warm, damp climates was ascertained by the author, as follows: Each of twelve brass pins, stuck vertically in a block of wood, had a colleted hairspring on its upper end. The block of wood was allowed to float in water and covered by a glass. One hairspring was left as it came from the factory, while each of the others had been treated with a solution of porpoise jaw oil and benzine, varying proportions of one to ten per cent of oil being used, the balance being benzine. The hairsprings were dipped into the solution, and, on withdrawing, were immediately placed between two folds of soft linen cloth. In any case not enough oil remained on the hairsprings to cause the coils to adhere. One per cent of nitric acid was added to the water, and after ten days the hairsprings showed on examination that they had rusted in proportion to the amount of oil that had been used. Another trial, without acid in the water, and with one hairspring treated with ether, one with benzine, one each with one, two, five and ten per cent of porpoise jaw oil in benzine, and one each with the same quantity of mineral oil in benzine, showed after thirty days that the hairspring treated with ten per cent mineral oil was slightly rusted, while those treated with ether and benzine were badly rusted, and all the others were rusted more or less.

~79. The Gumming and Drying of Oils~ is a very important consideration, the former being caused by oxidation, while the latter is due to evaporation.

In order to determine these properties in various oils the author used a number of watch glasses, their convex side being glued to a board. Two drops of oil were placed in each watch glass and spread over its concave surface, and the board placed in a covered box in which suitable air holes had been made, and allowed to remain in a temperature varying from 21 deg. to 37.5 deg. C. (= 70 deg. to 110 deg. F.) for 100 days, and at the end of that time the results shown in table VI were noted.

TABLE VI.

GUMMING AND DRYING OF OILS.

Temp. 21 deg. C. to 37.5 deg. C. = 70 deg. F. to 110 deg. F. Time 100 Days.

~80. The Viscosity Of Oils~ denotes an approximate measurement of their relative lubricating power.

Professor Thurston states[22] that "large consumers of oil sometimes purchase on the basis of this kind of test solely. It is regarded as satisfactory and reliable as any single physical or chemical test known, and is second only to the best testing machine methods.

The less the viscosity, consistently with the use of the oil under the maximum pressure to be anticipated, the less is, usually, the friction. The best lubricant, as a rule, is that having the least viscosity combined with the greatest adhesiveness. Vegetable oils are more viscous than animal, and animal more so than mineral oils. _The fluidity of an oil is thus, to a large extent, a measure of its value._"

The relation between the viscosity and the friction reducing power of oils has been determined by Mr. N. C. Waite[23] and others to be very close.

An oil having little viscosity is suitable for the escapement and lighter parts of the train, but is not a good lubricant for the bearings of the center pinion and barrel arbor and the mainspring, which require a more viscous lubricant; while a still greater viscosity renders it more serviceable on the stem winding mechanism (59) and in the pendant (60).

Again, an oil that possesses sufficient "body," or combined capillarity (32) and viscosity, to resist the tendency to be "squeezed" from between the bearing surfaces in the heavier parts of the mechanism will produce a _great excess of fluid friction_ in the lighter parts of the train and in the escapement.

~81. The Relative Viscosity of Oils~ is determined in several ways. Various machines have been devised for testing the lubricating properties of oils, but as the cheap ones are of no use, and as those which are reliable are so expensive as to prohibit their general use except in laboratories and large factories, a simple method of ascertaining the relative viscosity of oils is desirable.

The author used a piece of plate glass of suitable size on which one drop of each oil to be tested was placed near its end. The glass inclined from the horizontal, longitudinally--the angle of inclination being 6 degrees--and was placed in a constant temperature of 15.5 deg. C. (= 60 deg. F.)

The total distance in centimeters which each had traveled by the end of each day, as well as the appearance of the "track" which it had left is shown in table VII.

TABLE VII.

RELATIVE VISCOSITY AND GUMMING OF OILS.

Temp. 15.5 deg. C. = 60 deg. F. Inclination 6 degrees. Time 7 days.

----------------+---------------------------------------+----------- SYMBOLS | DISTANCE IN CM. | ACCORDING TO | TRAVELED BY OIL AT THE END | WIDTH TABLE III. | OF EACH DAY. | OF | | TRACK. ----------------+----+----+-----+-----+-----+-----+-----+----------- DAYS. | 1 | 2 | 3 | 4 | 5 | 6 | 7 | ----------------+----+----+-----+-----+-----+-----+-----+----------- E. K. w. |16 |18 |Stat.| ... | ... | ... | 18 | Medium. W. F. N. w. |15 |16.5| 18 | 19 | 20 |Stat.| 20 | " W. C. w. |17.5|19 | 20 |Stat.| ... | ... | 20 | Narrow. B. & K. w. |12.5|15 | 17.5| 20 |Stat.| ... | 20 | " C. L. Co. w. | 7.5|10 | 12.5| 15 | 17.5|Stat.| 17.5| Very wide. C. L. Co. No. 1.|15 |16.5| 18 |Stat.| ... | ... | 18 | Medium. Glyc. |15 |16.5| 18 |Stat.| ... | ... | 18 | " Sp. | 0 | 2.5| 5 | 7.5| 9 | 10 | 11 | Narrow. Ol. | 5 | 6.5| 7 |Stat.| ... | ... | 7 | " ----------------+----+----+-----+-----+-----+-----+-----+-----------

Table VII not only shows the relative viscosity of the various oils, but also their tendency to gum or dry (79.) The "width of the track" left by the oil is an indication of the cohesion (20) and adhesion (21) which exists, respectively, in the oil and between the oil and the glass. A narrow track denotes great cohesion and little adhesion; a wide track denotes great adhesion and little cohesion; while a medium track indicates that both properties are more nearly equal.

If an oil possess great adhesion and little cohesion it is more liable to resist the tendency to be squeezed out of bearings, but it is also more likely to spread.

Another test made in the manner just described (table VII) gave results as shown in table VIII:

TABLE VIII.

RELATIVE VISCOSITY AND GUMMING OF OILS.

Temp. 24 deg. C. = 75 deg. F. Inclination 7 degrees. Time 7.3 days.

------------------+------------------------------------------ SYMBOLS | DISTANCE IN CM. ACCORDING TO | TRAVELED BY THE OIL AT THE END TABLE III. | OF EACH DAY. ------------------+----+----+----+----+----+----+-----+------ DAYS. | 0.3| 1.3| 2.3| 3.3| 4.3| 5.3| 6.3 | 7.3 ------------------+----+----+----+----+----+----+-----+------ E. K. w. |14 |23 |26.5|28.5|29.5|31.5|32.5 |33 W. F. N. w. |12.5|20 |26.5|29 |31 |32.5|33.5 |34 W. C. w. |19 |24 |26.5|28 |29 |30.5|32 |33 B. & K. w. |14 |17.5|25 |27 |29.5|31.5|33 |33.5 S. B. & Co. w. c. |10 |20 |26 |26.5|27 |27.5|28 |28.5 C. L. Co. w. |29 |38 |40.5|42.5|43 |43.5|Stat.|43.5 C. L. Co. No. 1. |17.5|23 |27 |28 |29 |30 |31 |32 Glyc. |17.5|23 |28 |30 |32 |34 |35 |35.2 Alb. f. |15 |20 |29 |33 |35 |37 |38 |38.5 ------------------+----+----+----+----+----+----+-----+------

The author once heard a watchmaker say to a customer, when the latter called for a clock which had been left for repairs, "I have cleaned your clock thoroughly; and, as you are a good customer, I made as good a job of it as I could. _I even oiled it with watch oil._" This watchmaker evidently _thought_ he was right. It is hardly necessary to mention that a stock of oils of different viscosity should be kept on hand and intelligently used; the different bearings in any time keeping mechanism requiring oils of different viscosity. It is not to be supposed that the author means _each_ bearing in a watch is to have a separate oil applied; but a distinction should be made between the light and heavy pressures.

~82. The Effect Of Heat On Oils~ is very marked in all cases; some oils being much more subject to change than others, in viscosity and other properties, under the influence of an increase of temperature.

The lubricating power of an oil is decreased, while its tendency to spread is increased, with a rise of temperature. In order to ascertain the relative values of various oils in this respect the writer used a plate of glass 28 cm. x 40 cm., placed it flat on a table, and, depositing one drop of each oil near one of its longer edges, allowed it to remain in a temperature of 21 deg. C. (= 70 deg. F.) for 30 minutes. At the end of this time the glass plate was placed in a vertical position, with its edge near which the drops of oil had been deposited uppermost and horizontal. The time required by each oil to run down to the bottom, a distance of 25 cm., was noted. The width of the track, at a point 3 cm. from the location of the drop at the start, was measured when the oil had passed that point, and again measured _at the same point_ when the oil had reached the bottom.

The same test was repeated, with all the conditions similar except that the temperature of the room was raised to 38 deg. C. (= 100 deg. F.) before the oil was placed on the glass; but the glass was allowed to remain in this temperature also for 30 minutes.

The results of both experiments are shown in table IX.

TABLE IX.

RELATIVE VISCOSITY, COHESION AND ADHESION OF OILS.

Temp. 21 deg. C.(= 70 deg. F.) and 38 deg. C. (= 100 deg. F.) Inclination Vertical.

-----------------+----------------+--------------------------------------- SYMBOLS |MINUTES REQUIRED| WIDTH OF TRACK IN MM. AT A POINT ACCORDING TO | TO FLOW 25 CM. | 3 CM. BELOW STARTING TABLE III. |AT A TEMPERATURE| PLACE WHEN THE OIL HAD FLOWED | OF | | +-----------------+--------------------- | | Temp. 21 deg. C |Temp. 38 deg. C. | | (=70 deg. F.) | (=100 deg. F.) -----------------|-------+--------+-------+---------+--------+------------ | 21 | 38 | | | | |deg. C.| deg. C.| | | | | =70 | =100 | 3 CM.| 25 CM. | 3 CM. | 25 CM. |deg. F.| deg. F.| | | | -----------------+-------+--------+-------+---------+--------+------------ E. K. w. | 21 | 14 | 5 | 5 | 5 | 5 W. F. N. w. | 18 | 12 | 5 | 5 | 5 | 5 D. C. S. w. | 20 | 13 | 5 | 5 | 5 | 5 D. C. S. ch. | 15 | 10 | 5 | 5 | 5 | 5 D. C. S. cl. | 20 | 11 | 5 | 5 | 5 | 5 W. C. w. | 13 | 8 | 5 | 1 | 5 | 1 B. & K. w. | 13 | 11 | 5 | 0 | 5 | 0 S. B. & Co. w. c.| 15 | 11 | 6 | 6 | 6 | 8 C. L. Co. w. | 17 | 15 | 6 | 7 | 7 | 8 C. L. Co. No. 1. | 15 | 10 | 6 | 6 | 5 | 5 Glyc. | 14 | 10 | 6 | 6 | 5 | 8 Alb. f. | 14 | 10 | 6 | 6 | 5 | 6 Sp. | 10 | 7 | 6 | 1 | 5 | 0 Ol. | 14 | 12 | 5 | 2 | 5 | 1 -----------------+-------+--------+-------+---------+--------+------------

While the relative viscosity of oils in varying high temperatures is shown in table IX, the width of the track indicates the same properties as were explained in reference to table VII. Thus it is seen that the third and fifth columns of figures denote the relative adhesion of the oils, approximately according to the value of the figures; while the fourth and sixth columns exhibit their relative cohesion, and absence of adhesion, approximately according to the inverse value of the figures. Thus the tendency of the oil to spread, in the warm temperature to which time keeping mechanisms are frequently subjected, is indicated.

~83. The Effect Of Cold On Oils~ is very observable in some varieties, converting them into greases, or even into hard, waxy solids. For out-of-door work unguents must be selected that will "feed" at any temperature to which they are exposed in the working of the bearings to which they are applied.

The author has subjected various oils to a low degree of temperature, using a sufficient number of thin glass test tubes of 3 cubic centimeters capacity,[24] into each of which 2 cubic centimeters of the oils to be tested were poured. The test tubes were then tightly corked and properly secured to a thin board, and placed in a temperature of -15 deg. C. (= 5 deg. F.) the condition of the oils being noted at various intervals, the result of which is shown in table X.

~84. The Variations of Viscosity of Oils in Varying Temperatures~ always create fluctuations of their friction reducing power; while the variations of fluid friction which result are also of great importance in horology. When it is known that the viscosity and lubricating power of an oil are usually (80) very closely related, it is seen that change of temperature has an exceedingly important effect upon oils, even for general lubricating purposes; but particularly so when they are applied to small and delicate mechanisms.

An oil of the proper viscosity at ordinary temperatures may be very unsuitable in an extreme of heat, or cold, to which timepieces are frequently subjected--on account of being too limpid in high temperatures to properly separate the rubbing surfaces; while in low temperatures it may become so viscous as to seriously impede the motion of the escapement and the lighter parts of the train.

TABLE X.

RELATIVE EFFECT OF COLD ON OILS.

Temp. -15 deg. C. (= 5 deg. F.) Time of Exposure = 6 hours

-----------------+------------------------------------------ SYMBOLS | ACCORDING TO | CONDITION OF OIL. TABLE III. | -----------------+-------+-------+-------+--------+--------- TIME. |15 MIN.|30 MIN.|1 HOUR.|6 HOURS.|ORDER OF | | | | |VISCOSITY -----------------+-------+-------+-------+--------+--------- E. K. W. w. | ... | ... | ... | ... | 2 W. F. N. w. | ... | ... | t-f. | t-f. | 4 D. C. S. w. | ... | ... | ... | ... | 2 D. C. S. ch. | ... | ... | ... | ... | 2 D. C. S. cl. | s-s. | s-s. | s-s. | s-s. | 6 W. C. w. | ... | ... | ... | ... | 2 B. & K. w. | ... | ... | ... | ... | 2 S. B. & Co. w. c.| ... | ... | ... | ... | 1 C. L. Co. w. | s-s. | s-s. | s-s. | s-s. | 5 C. L. Co. No. 1. | s-s. | s-s. | s-s. | s-s. | 7 Glyc. | ... | ... | ... | ... | 1 Alb. f. | ... | ... | ... | ... | 3 Sp. | s-s. | s-s. | s. | v-s. | 8 Ol. |v-t-f. | s-s. | s. | v-s. | 9 -----------------+-------+-------+-------+--------+--------

T. F. = Thickly fluid; or like honey. V. T. F. = Very
thickly fluid; or like jelly. S. S. = Semi-solid; or like
butter at 60 deg. F. S. = Solid; or like butter at freezing
point. V. S. = Very solid; or like paraffin wax.

The figures in the last column denote the apparent relative
viscosity, as ascertained by inverting the test tubes
repeatedly.

Again, even if the oil were viscous enough in high temperatures to resist the tendency to be "squeezed" out of the bearings, the _rate_ of the timepiece would be seriously affected by the variation of solid and fluid friction--especially the latter--caused by a variable viscosity of the oil.

When a watch, chronometer or clock has been so adjusted as to keep a _maximum even rate_, the oil is one of the factors of the variation which has been overcome; and it is obvious that if another oil be used, in which a greater or less variation of viscosity exists than in the oil with which such timepiece was lubricated prior to adjustment, the variation so produced will be more or less observable.

It is, then, evidently necessary to be able to ascertain, with the greatest possible exactness, what change in this respect is produced in the various oils by a change of temperature. The means previously given (81-83) have their value; but when supplemented by a method for determining the particular property under consideration, the results obtained are exceedingly interesting and valuable. On account of the importance of this matter the author has made investigations in this direction, using a "viscosimeter" as shown at Fig. 15, and of which the following is a description:

AA represents an ordinary retort stand, with adjustable arms, BB, for holding in position the thermometer C, and the funnel DD capable of holding about one pint of water. EE is the viscosimeter proper, a glass tube, swollen at the lower end, and terminating in a circular orifice of 1 millimeter (= .04 inch) in diameter;[25] being a "pipette" holding one cubic centimeter of oil between the dotted lines U and O.

F is a flexible gum elastic tube fitting with an air-tight joint to the upper end of the glass tube. The funnel is closed at its lower end by a tightly-fitting cork H, in which an opening is made, through which opening the pipette passes and projects slightly below. G is a small, shallow vessel, preferably of glass, of sufficient capacity to receive the contents of the pipette. S is a syphon composed of a glass tube in two sections--united by a short piece of rubber tube on which the device P pinches by the adjustment of the lever L--the bent section beginning near the bottom of the funnel, while the straight section terminates below the level of the table on which the retort stand is placed.

In operating with this, the author proceeded as follows: The funnel was partially filled with water, and hot water added until its temperature reached 43 deg. C. (= 110 deg. F). A sufficient quantity of the oil to be tested was placed in the glass vessel G, and drawn into the viscosimeter by gentle suction of the mouth until it exactly reached the line U, where it was retained, by a slight pressure with the thumb and finger, for five minutes, the temperature of the water in the funnel being kept constant. At the end of that time, after being sure that all the conditions as to temperature and quantity of oil were satisfied, the pressure of the thumb and finger was relaxed, when the oil began to drop through the lower end of the pipette.

The time required for the upper surface of the oil to fall from U to O was carefully ascertained by means of a "stop watch," and the number of seconds noted. In case of doubt the test was repeated.

The temperature of the water in the funnel was then lowered by the addition of ice, to 38 deg. C. (= 100 deg. F.), when the operation was again performed as just described. This was repeated at regular intervals of temperature down to 4 deg. C. (= 40 deg. F), when the water was again heated, the pipette thoroughly cleansed by introducing benzine into the pipette in a manner similar to that by which the oil was introduced. The surplus water which accumulated in the funnel was allowed to escape through the syphon by relaxing the lever of the pinching device. It is obvious that the number of seconds, in each case, corresponds to the viscosity. Other oils were put through the same course, the results obtained being shown in table XI.

TABLE XI.

RELATIVE VARIATIONS OF VISCOSITY OF OILS IN VARYING TEMPERATURES.

-----------------+---------------------------------------------- SYMBOLS | SECONDS REQUIRED FOR 1 C. C. OF OIL TO FLOW ACCORDING TO | THROUGH AN ORIFICE OF 1 MM. (= .04 IN.) TABLE III. | ---------+-------+----+-----+-----+-----+-----+-----+-----+----- | CENT. | 4.5| 10 | 15.5| 21 | 26.5| 32 | 37.5| 43 TEMP.{A} +-------+----+-----+-----+-----+-----+-----+-----+----- | FAHR. | 40 | 50 | 60 | 70 | 80 | 90 | 100 | 110 ---------+-------+----+-----+-----+-----+-----+-----+-----+----- E. K. w. | 25 | 20 | 17 | 15 | 10 | 8.5| 7 | 6 W. F. N. w. | 27 | 20 | 14 | 11 | 9 | 8 | 7 | 6 D. C. S. w. | 32 | 23.5| 19 | 15 | 12.5| 11.5| 9.5| 8 D. C. S. ch. | 28 | 23 | 17 | 14 | 11.5| 9 | 7 | 6 D. C. S. cl. | 29 | 20 | 17 | 14.5| 11 | 8.5| 7 | 6.5 W. C. w. | 24 | 20 | 18 | 13 | 11.5| 10 | 8 | 7 B & K. w. | 46 | 35 | 25 | 20 | 17 | 15 | 11.5|10 S. B. & Co. w. c.| 21 | 16 | 11.5| 10 | 9 | 8 | 7 | 6.5 C. L. Co. w. | 14 | 10 | 9 | 6.5| 5 | 4.5| 4 | 3.5 C. L. Co. No. 1. | 32 | 28 | 12.5| 10 | 8.5| 7.5| 6.5| 6 Glyc. | 19 | 13 | 10 | 9.5| 7.5| 6.5| 5.5| 5 Alb. f. | 25 | 19 | 16 | 13 | 10 | 8 | 6.5| 5.5 -----------------+----+-----+-----+-----+-----+-----+-----+-----

[Note A: The readings of the Centigrade and Fahrenheit scales given here are not exactly equivalent; but they are near enough for all practical purposes.]

~85. Mixed Oils~ have been tried by many who have been desirous of obtaining a better lubricant. A mixture of different kinds of animal or vegetable oils--or a combination of both--has usually proved worse than any single one of the components; as, when it is known that "alterations[26] of composition occur in the animal and vegetable oils with exposure to air and light and with advancing age" (74-2), it is obvious that this chemical action is accelerated by a mixture.

The mineral oils are not subject to such alterations to any serious extent; and, when they are compounded with animal or vegetable oils, the resulting mixture partakes of the good qualities of both, according to experiments which the author has made. It would make this paper[27] too lengthy to insert the results; however, a future opportunity may not be wanting.

~86. Various Manufacturers~ of watches, chronometers and clocks, have favored the writer with more or less valuable information in answer to queries on the subject, which has been tabulated and which is shown in table XII.

It is necessary to know just what kind of oil has been used by the manufacturer of a time piece for three reasons:--

(1.) If some of the bearings need a small quantity of oil, being otherwise in such good condition--because of never having been used, in fact "new"--that it is unnecessary to take all the mechanism apart and clean it, it is very important that the operator know what kind, or variety, of lubricant has been previously used, in order not to "mix oils;" or, if a mixture is thus made, to make it intelligently. (85.)

(2.) When the oil which has been applied in the factory has not performed its functions properly in any part of a time piece, it is necessary to know what particular variety of lubricant has been used in order to substitute an oil which possesses the properties lacked by the oil previously used. (61.)

(3.) In a watch which has been so adjusted as to keep a maximum even rate, the oil is one of the factors of the variation which has been overcome. It is necessary, then, on putting the watch in order, to employ a lubricant which possesses the same variation of viscosity as the oil which was used during adjustment. (84.)

Some other interesting facts are shown in table XII, as well as the foregoing. The queries were as follows:--

QUESTIONS ASKED.

1. What oil do you use?
2. What oils have you tried?
3. What has been your experience with mixed oils?
4. Do you use the same grade of oil on all parts of your ----?
5. If not, what is your practice?
6. What amount of oil do you use annually?

The answers are given in Table XII.

~87. Impurities in Oils~ and all foreign matter exert a very injurious effect. The method of sealing the bottles with sealing wax or gum labels should be avoided; the former, as the wax is brittle and liable to break in very fine pieces which lodge around the cork from whence they get into the oil; and the latter because the gum with which it is caused to adhere remains on the bottle, only to be absorbed by the oil.

Paraffin wax makes a very good sealing material, as it is not brittle, and keeps the oil protected from the air. An extra long cork should accompany each bottle.

TABLE XII.--ANSWERS TO QUESTIONS.

TABLE XII.--ANSWERS TO QUESTIONS.--CONTINUED.

-------------+----------+----------+---------+-----+--------------+--------
Manufacturer.| 1 | 2 | 3 | 4 | 5 | 6
-------------+----------+----------+---------+-----+--------------+--------
| | Steven- | | | On all bear- |
| | son's. | | |ings the same |
{1}|Sine Dolo | Black- | None. | No. | oil, but on | 1
| | fish. | | | mainspring |gallon.
E. Howard | |Porpoise- | | | a rock oil. |
Watch & | |jaw. Rock.| | | |
Clock Co. +----------+----------+---------+-----+--------------+--------
{2}|Kelley's. | | None. |Yes. | | 1
| | | | | |gallon.
+----------+----------+---------+-----+--------------+--------
{3}|Rock Oil. | | Satis- |Yes. | | 10
| | |factory. | | |gallons.
-------------+----------+----------+---------+-----+--------------+--------
| | | | |Light oil for |
H. H. Hein- | |Every kind|Unsatis- | | small pivots |
rich,Chrono- | Stull's. | in the |factory. | No. | and heavier |1 pint.
meter Maker. | | market. | | |oil for larger|
| | | | | pivots. |
-------------+----------+----------+---------+-----+--------------+--------
| | Stull's. | |Yes. |A light oil on|
New Haven | Stull's. | Black- |Unsatis- | |clock-watches.| 20
Clock Co. |Kelley's. | fish. |factory. +-----+--------------+gallons.
| |Porpoise. | |Yes. |A heavy oil on|
| | | | | clocks. |
-------------+----------+----------+---------+-----+--------------+--------
Ingraham | | Rock. |Unsatis- | | | 12
Clock Co. |Porpoise. | Mixed. |factory. |Yes. | |gallons.
| | | | | |
-------------+----------+----------+---------+-----+--------------+--------
| | Stull's. | | | |
Waterbury | Stull's. | Smith's. | None. |Yes. | | 15-20
Clock Co. | | Steven- | | | | gals.
| | son's. | | | |
-------------+----------+----------+---------+-----+--------------+--------
Wm. L. Gil- | | Nye's. | | | |
bert Clock | Nye's. | Smith's. | | | | 10-12
Co. | |Kelley's. | | | | gals.
| |Comstock's| | | |
-------------+----------+----------+---------+-----+--------------+--------

[Note 1: Watch.]

[Note 2: Regulator.]

[Note 3: Tower Clock.]

Then again some workmen leave the oil bottle standing open, which is obviously a very careless proceeding. The author has seen a bottle one quarter full of dust, the oil still being used from the top. When oil is to be placed in the oil-cup, it should be done by using a small, clean glass rod--kept for the purpose--and never poured out of the bottle.

The oil cup should always have the cover on except when taking oil from it. Before it is refilled it should be very carefully cleaned.

The oiler should be perfectly clean, that kind which has a hexagonal nut on the handle and a gold tip being very excellent. Some careless workmen wipe the oiler on the back of the hand, on the clothes, on a dirty rag, on an old chamois, etc. The tip of the oiler should never touch the hand or fingers, as the acids in the perspiration are sure to cause a bad effect on the oil.

The following is a list of "oilers" which the author has seen used:--Peg wood, broom straw, quill, toothpick, match-stick, screw driver, tweezers, rat-tail file, piece of copper wire, horse-shoe nail, steel pen.

If dust be on the bench paper, or in the movement tray, the pivots will surely transfer some of it to the bearings when the wheels are being put to place.

The scape-wheel, mainspring and other parts, the rubbing surfaces of which may come in contact with the fingers, should be so handled as to allow no perspiration to become deposited on any surface which may afterwards require oiling, as the acids contained in the perspiration will exert an injurious effect on the oil.

The owners of watches sometimes subject them to very hard treatment by using perfumes, etc., and then some people perspire more than others, while the perspiration of some persons contains more acids, or is more rancid, than that of others. For these reasons the method of testing oil by putting it on watches kept to loan to customers as Saunier recommends cannot be relied on.

Oils should be kept in a clean, cool, dark place. The wrapper or label on the bottle should be dark blue or black, to exclude all light, as, if this is not done, the oil will be more liable to decomposition, except in the case of a mineral oil, which is not affected by light. All vegetable and animal oil which has been "bleached" by exposure to the light is more liable to decomposition on exposure to air than that which is unbleached.

~88. The Effect of Age on Oils.~ Writing on this subject Mr. Henry G. Abbott[28] states as follows: "There is a popular fallacy existing in the trade that oils should be used when fresh, and even that acknowledged authority, Saunier, says, 'do not buy from motives of economy bottles that have laid for years in the shop.' This may be true and probably is in regard to animal and vegetable oils, which are likely to become rancid if kept for a long time, but William F. Nye, one of the largest and most celebrated manufacturers of fine watch and chronometer oils in the world, declares that blackfish oils are improved by age, and his oils are seldom placed on the market in the same year as obtained. We are indebted to the same authority for the statement that oils of this kind are clearer and more brilliant after some years than fresh oils." Though Mr. Abbott has made some very valuable additions to the literature of the profession, the author begs permission to call attention, in reference to this, to the following facts:

Mr. Abbott says that vegetable and _animal_ oils are likely to become rancid if kept for a long time, but _blackfish_ oils are not. Brant[29] states that the porpoise or _Phocoena communis_, Cuv., and the blackfish, or _Phocoena globiceps_, are of the subdivision _Delphinodea_, or dolphins, of the family of _Cetacea_, or whales, an order of the vertebrated mammiferous marine _animals_. Adler Wright[30] states that "the term 'train oil,' strictly speaking, applies to any oil extracted from the blubber of cetaceans and the allied marine mammalia, such as the seal, porpoise, dolphin and walrus." Huxley classes among cetacea the dolphins, porpoises, grampus and narwhal. Authorities might be quoted _ad infinitum_ to show, not only that porpoise-jaw oil and blackfish-melon oil _are animal oils_, but that they possess properties similar to other animal oils as far as their liability to decompose by age, more or less, is concerned.

Furthermore, Thurston[31] states that "all vegetable and animal oils are compounds of glycerine and the fatty acids. When they become old decomposition takes place, and acid is set free, by which action, as is commonly said, the oils become rancid." Thus Saunier is borne out in his admonition.

~89. In Conclusion~, the author wishes to state, that as he has been able to find but little in the literature of the craft in English, French or German, he has pursued the study of the "properties and relative values of lubricants in horology" upon lines which have suggested themselves as being best adapted to give good results. As much that is herein contained is new and original in its application in horology, the theories advanced may be in some respects incorrect. The tests of various oils have, no doubt, been subject to personal error; but it has been the earnest desire of the author to give the subject the attention it deserves.

In order that truth may prevail and that justice may be done to the various manufacturers of oils, as well as to the author and his subject, he will again request criticism through the trade press in any matter in which he may seem to be at fault. He further wishes that others may become interested, and that the makers and repairers of watches, chronometers and clocks, as well as the manufacturers of oil, will further assist in these investigations by making similar or other experiments, and report the result of the same through the trade press in order that this very important subject may be thoroughly understood.

In furtherance of this object the author will furnish samples of oils _free_ to anyone wishing to make experimental tests of _any_ kind, on condition that the results of such tests shall be published or communicated to the author for future publication. Address, W. T. Lewis, President Philadelphia Horological Society, Philadelphia, Pa.

FOOTNOTES:

[12] Thurston. Friction and Lost Work in Machinery.

[13] As the fish from which these oils are obtained are of the mammalia order, their oils are classed among the animal oils.

[14] The Horological Journal, Apr., 1881. Vol. xxiii. Page 98.

[15] Pharmacopoea Germanica. 1882.

[16] The National Dispensatory. 1884.

[17] Saunier, Watchmaker's Hand-Book, p. 104, Eng. Edition; p. 129, Am. Edition.

[18] Brannt. Animal and Vegetable Fats and Oils.

[19] Paper read in the Chemical Section, British Association, Plymouth Meeting, 1879.

[20] Swansea Meeting. British Association, 1880.

[21] This work is compiled from a course of lectures delivered by the author before the Philadelphia Horological Society, 1896.

[22] Thurston. Friction and Lost Work in Machinery.

[23] Proceedings N. E. Cotton Manufacturers' Association, Nov. 28, 1880.

[24] The average teaspoon holds 5 cubic centimeters.

[25] 1 millimeter = .039 + inch.

[26] Thurston. Friction and Lost Work in Machinery.

[27] This work is compiled from a series of papers read and lectures delivered by the author before the Philadelphia Horological Society, 1896.

[28] Abbott. The American Watchmaker and Jeweler, 1892, page 249.

[29] Brant. Animal and Vegetable Fats and Oils, pages 297-299.

[30] Adler Wright. Oils, Fats and Waxes, and Their Manufactured Products, p. 292-293.

[31] "Friction and Lost Work in Machinery."

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